Solar Magnetic Eruption Disturbances

Solar Magnetic Eruptions (SME) may cause the ejection of magnetized
gas into interplanetary space. These eruptions, known as Coronal
Mass Ejections (CMEs), may generate interplanetary transient disturbances
involving shocks and magnetic clouds. If these disturbances encounter
the Earth's magnetic field they can cause geomagnetic storms (observed
as polar auroras). In severe cases these storms can damage technological
systems like satellites, communications and navigation systems,
power lines, as well as pose danger to astronauts.

Although CMEs are quite frequent (one or two a day during periods
of solar maximum activity), only fraction of them hit the Earth's
magnetosphere and cause geomagnetic storms. Severe storms occur
with a frequency of about 100 times over the 11-year cycle of solar
activity. Extremely severe storms occur about 4 times during this
period. As humans depend more and more on advanced technological
systems, and as they expand into the space environment, the knowledge
of "space weather" becomes more important. Numerical modeling
represents an important tool for understanding and eventually forecasting
space weather.

The results of this study were obtained from a numerical simulation
using a 3D magneto hydrodynamic (MHD) heliospheric model that describes
the solar wind density, temperature, magnetic field components and
velocity components. The MHD model is driven by a solar eruption
simulated using a coronal model developed by the Science Application
International Company (SAIC). The heliospheric computations are
carried out on a spherical grid, with the Sun located at the center,
ranging from 20 to 270 solar radii.

Interplanetary
Magnetic Field Disturbance Following an SME

This is a simulated interplanetary disturbance
caused by a solar magnetic eruption that is oriented directly towards
earth. Solar wind density (blue isosurface) and magnetic field (red
field lines) are shown. The Sun is five times larger than reality.
The Earth is also scaled to five solar radii.